Enamels are prepared by applying hyaline glaze on a surface of a metal plate. General enamels may be used in cooking appliances such as microwaves, electronic ranges, and the like. Enamels may be classified as acid proof enamels for antioxide and heat-resisting enamels which are endured at a high temperature according to a kind or use of glaze. Also, enamels may be classified as aluminum enamels, zirconium enamels, titanium enamels, and soda glass enamels according to a material added into the enamels.
Generally, cooking appliances are home appliances for heating and cooking foods using a heat source. Slops generated during the cooking may be attached to an inner wall of a cavity of such a cooking appliance. Thus, after foods are cooked in the cooking appliance, it is necessary to clean the inside of the cavity. Also, the cooking of foods may involve a high temperature, and the inner wall of the cavity may be exposed to organic materials and alkali components. Thus, when enamels are used in cooking appliances, the enamels should have heat resistance, chemical resistance, wear resistance, and contamination resistance. Therefore, an enamel composition for improving the heat resistance, the chemical resistance, the wear resistance, and the contamination resistance may be required.
Particularly, a pyrolysis method in which contaminants burn at a high temperature to make ashes or a method using strong alkali detergent may be used as technologies for easily cleaning enamels used in general ovens. As a result, since the enamels are exposed to the high temperature and strong alkali detergent, enamels having chemical properties such as high heat resistance and chemical resistance are required.
Also, to prepare the above-described enamels, various kinds of glass frits may be used. That is, to prepare the enamels, glass frits having components different from each other may be used. In this case, various kinds of glass frits may be prepared, and then a process of mixing the glass frits with each other may be performed. Thus, high energy consumption and high faulty rate may occur.